Developed these pens for embroidery artists like you, looking for creative solutions. These pens create delicate, visible, pattern lines that are easily covered by the tiniest stitches. Use these to transfer your own original designs to fabric! These also work perfectly for tracing and transferring PDF printout patterns and iron-on transfers that no longer imprint! The ink will transfer to pre-heated fabric (and also wood and cardstock) with a hot, dry iron.